ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 31 



epiphysis and that of the dogfish. In the course of the pineal tract the 

 frog agrees with Teleosteans and differs from Selachians, for there is 

 neither habenular tract nor epiphysial decussation. J. A. T. 



Epiphysis Nerves in Sprat and Herring. — Nils Holmgren {ArTciv 

 ZooL, 1918, 11, No. 25, 1-5, 2 figs.). In Clupea the habenular nerves 

 are both united with habenulae, and there is also a posterior commissure 

 ■connexion. Now this is the sturgeon-stage in the development of the 

 smelt (Osmerus), and it persists in some varieties of Osmerns ; so that 

 Ciupea may be said to be in this respect phyletically older than Osmerus. 

 In the development of Osmerus, the second stage, the Amia stage, shows 

 the left habenular nerve going to the habenula, while the right goes to 

 the posterior commissure. This stage is also represented in some 

 varieties of Osmerus. The third stage in the development of Osmerus, 

 the Salmonid stage, shows both habenular nerves going to the posterior 

 commissure. The more important variations of Osmerus as regards 

 epiphysis nerves may be described as atavistic. J. A. T. 



Autotomy in Pocket Mice. — F. B. Sumner and H. H. Collins 

 {Biol. Bulletin, 1918, 34, 1-6, 2 figs.). When a specimen of Perogna- 

 iJnis fallax fallax is seized by the tail it often gives its body a curious 

 gyrating twist, and the tail breaks across a vertebra (observed in eight 

 cases). There is no regeneration after the autotomy, except that a tuft 

 of hairs grows on the severed stump. Autotomy was also observed in 

 P. panarnintinus hangsi, a small desert pocket mouse, while in P. boylei 

 rotvleyi the skin breaks and slips off very readily. In both cases the 

 animal makes what appear like vigorous and well-directed efforts to effect 

 the severance. J. A. T. 



Experiments on Tadpoles. — Bennett M. Allen {Proc. Amer. 

 JSoc. Zool. in Anat. Record, 1919, 15, 352-3). Tadpoles of Rana and 

 Bufo from which the first beginning of both thyroid and pituitary 

 glands had been extirpated, developed in precisely the same manner as 

 did those from which the pituitary glands alone were removed. Eight 

 tadpoles were living eight months after the removal of the glands. 



J. A. T. 



Endocrine Glands of Frog and Toad. — Bennett M. Allen 

 {Proc. Amer. Soc. Zool. in Anat. Record, 1919, 15, 353). Tadpoles 

 upon which thyroidectomy had been attempted metamorphosed tardily 

 and were of large size. They showed more or less imperfect thyroid 

 glands. Three operated on for the removal of the hypophysis showed 

 small size at metamorphosis and light colour. They had an imperfect 

 hypophysis. Some other interesting experiments were made. J. A. T. 



Endocrine Glands of Toad. — Mary Elizabeth Larson {Proc. 

 Amer. Soc. Zool. in Anat. Record, 1919, 15, 353-4). As Rogers showed, 

 extirpation of the thyroid is correlated with increase in the anterior 

 lobe and pars intermedia of the pituitary body. This is confirmed by 

 numerous careful experiments. The minute structure of the pituitary 

 body is notably affected. J. A. T. 



